Problem using sprintf with LCD

johnt — Fri, 02 Nov 2012 11:55:19 GMT

Hello everybody,

I'm trying to print the value of a int variable to one LCD but it's not working properly, I've tried many things but I would like to know how can I include a int variable to a normal a string that I want to print to the LCD.

I can only print normal texts to the LCD but without variables, for example doing this:

char *text="Hello world";

while (*text)

{

senddatatoLCD (*text++); //Function made to send data to LCD in 2 lines using 4 bits only.

}

I would like to build a string with value of int variable already included and then just send this string with a while loop as I've on the example shown before.

Something like this: sprintf (*string, "The value: %d", var);

and the use the *string to print it to the LCD.

Does someone knows how to do it?

Thanks in advance.

Re: Problem using sprintf with LCD

TomE — Thu, 29 Oct 2020 09:08:54 GMT

This is very basic C programming. You need "string" to be an ARRAY to define some storage for sprintf to write to.

char vString[100];
char *pText;
int nVar = 123

sprintf(vString, "The value: %d", nVar);
pText = vString; /* this is the same as "pText = &vString[0];" */
while (*pText)
{
    ... And so on, the same as before ...

See if you can get an old K&R C book and work through that.

Tom

topic Re: Problem using sprintf with LCD in ColdFire/68K Microcontrollers and Processors

Problem using sprintf with LCD

Re: Problem using sprintf with LCD